This invention relates to a telephone communication control system and more particularly to a control module adapted to supply operating power to a monitored unit while enabling either of the two users to communicate by means of a telephone connection, and to selectively disconnect the monitored unit.
Presently there is a need in many industrial uses for a two way communication system to enable a user at a first site to communicate with a user at a second site. This, of course, is a function of a telephone system in general. In such industrial uses as on a construction site, the users of the phone system oftentimes monitor the progress of a piece of apparatus in order to control its performance and to determine whether the task is progressing properly. The uses of the telephone on construction sites are many. For example, on many construction sites workers use apparatus which is designated as a wire puller and vacuum system. Such wire pullers are well known in the art and essentially enable construction workers to lay and direct cable in suitable conduits or trenches. In this manner, the wire puller is located at a central position. Wire or cable is fed from a feeding site and is directed to the wire puller from a huge reel or source of wire. At the other end of the wire puller, additional men are located to direct the wire with the aid of the puller through the various conduits to hence route the wire or cable as desired. In any event, as one can imagine, noise level on a construction site is extremely high. There also exists many sources of radio frequency interference due to the operation of heavy construction equipment which is conventionally employed on a construction site.
In present operations when a task such as wire pulling is performed, the construction workers use conventional communication systems such as field phones or radio transmitters and receivers to communicate between the cable feed site and the pulling station. The reason for this is that during the course of pulling the cable, many things can occur which will interrupt the pull. For example, the cable on the feed spool can be depleted and hence, the pulling site must be informed of this in order to stop the pull and to splice or insert additional cable. Cable can become jammed or cut and hence, the wire puller must be inactivated and the pull must be stopped to avoid injury. In the use of a telephone system, in many instances the wires between the pulling and feed sites may be inadvertently cut or damaged and hence, communication would be lost.
A wire puller, as indicated, is a conventional piece of equipment and many examples exist in the prior art. A particularly effective puller is manufactured by the Greenlee Tool Co. of Rockford, Illinois. These pullers provide large torque and hence, create great forces on the wire or cable. Accordingly, if the phone circuit should be disconnected or the cable jammed and the wire puller not stopped, the cable can be damaged or substantial injuries can occur to the construction workers. This has happened numerous times in the past and is a great source of difficulty for the construction worker and the contractor in general.
It will be understood that the problem described above in conjunction with the wire puller is also a problem in regard to the operation of other pieces of heavy equipment in heavy noise environments such as a construction site and where the progress of a particular job is monitored between two extreme sites.
It is therefore an object of the present invention to provide a control apparatus which supplies operating power to a machine and which system enables communication between a first and a second site to enable a user at either site to immediately disconnect power to the machine when a dangerous situation is detected.